Luminaire utilizing a transparent organic light emitting device display

ABSTRACT

The examples relate to various implementations of a software configurable luminaire and a transparent display device for use in such a luminaire. The luminaire is able to generate light sufficient to provide general illumination of a space in which the luminaire is installed and provide an image display. The general illumination is provided by additional light sources and/or improved display components of the transparent display device.

TECHNICAL FIELD

The present subject matter relates to luminaires that provide generalillumination, and are software configurable to present images utilizinga transparent organic light emitting device (OLED) display as well as totransparent OLED displays and elements for use in such displays.

BACKGROUND

Electrically powered artificial lighting has become ubiquitous in modernsociety. Electrical lighting devices are commonly deployed, for example,in homes, commercial buildings and other enterprise establishments, aswell as in various outdoor settings.

Lighting devices take many forms, for example, ranging fromaesthetically appealing residential use luminaires to ruggedizedindustrial lighting devices configured according to the environment inwhich the luminaire is located. A primary function of a lighting deviceis to provide general illumination that complies with governmentalregulations and industry standards applicable to the environment inwhich the lighting device is installed.

Examples of other uses of lighting in combination with displaytechnologies includes various configurations of signage that includelight sources as backlighting that are positioned behind a designfeature such a diffuser or screen with an image or wording. Examples ofsuch backlit signage includes advertising signs, door exit signs andother examples of signage that would benefit from backlighting. Some ofthe signs may be controllable to change wording or an image presented onthe display device of the sign. In some instances of advertisingsignage, a transparent display can be used to provide advertisingwithout obstructing a view of either the interior of a store when viewedfrom the exterior or vice versa, as well as providing an easilychangeable design. However, backlit signage without additional lightingis not typically configured to provide general illumination thatcomplies with governmental regulations and industry standards applicableto the environment in which the signage is installed.

There have been more recent proposals to develop transparent displaysusing organic light emitting devices (OLEDs) for purposes of providingaugmented reality experiences, and to provide smart windows, doors oreven furniture. However, due to the construction of these transparentdisplays, the optical transmissivity of some of these displays is only45% with a pixel size of 0.63 millimeters. This lack of transmissivityhinders full utilization of the transparent attributes of thetransparent display for purposes other than the augmented realityexperience or as smart windows.

Although more recent transparent display proposals provide a greatertransmissivity than previous attempts, the transmissivity of thetransparent display device may be further improved to provide greatertransmissivity.

Recent developments in the use of OLED devices have enabled colortunable light sources. In an example, the Fraunhofer Institute has alsoshown that a tunable OLED device that emits a range of different colorsmay be formed by arranging different color light emitting OLEDs over oneanother. The OLED described by the Fraunhofer Institute is used in alighting device to provide tunable light ranging from a warm yellowcolor to a cooler blue color.

Furthermore, there have been proposals to use displays or display-likedevices mounted in or on the ceiling to provide variable lighting. TheFraunhofer Institute, for example, has demonstrated a lighting systemusing luminous tiles, each having a matrix of red (R) LEDs, green (G),blue (B) LEDs and white (W) LEDs as well as a diffuser film to processlight from the various LEDs. The LEDs of the system were driven tosimulate or mimic the effects of clouds moving across the sky. Althoughuse of displays with a lighting device allows for variations inappearance that some may find pleasing, the displays or display-likedevices are optimized for image output and do not provide particularlygood illumination for general lighting applications.

Opportunities exist to improve upon the transmissivity of transparentOLED display devices for various applications, including for use as (oras part of) a lighting device.

SUMMARY

Hence, for the reasons outlined above or other reasons, there is roomfor further improvement in lighting devices based on display devicesand/or in transparent display device technologies.

An example of a luminaire as disclosed herein includes a lighting devicethat emits general illumination light, a spatial modulator device and atransparent display device. The lighting device may be any light sourcethat is controllable to emit general illumination light of a selectedintensity, e.g. that complies with governmental guidelines orregulations and/or with industry standards. The spatial modulator deviceprocesses light input thereto into output light thereof having aspecified beam shape and/or beam direction. The spatial modulatorincludes an input, controllable optics and an output. In the luminaireexample, the spatial modulator input receives the general illuminationlight emitted by the lighting device, the controllable optics spatiallyprocess the input general illumination light, and the processed generalillumination light is output via the output, e.g. having a specifiedangular direction and/or shape. The luminaire in this example alsoincludes a transparent display device optically coupled to the output ofthe spatial modulator device. The transparent display device isconfigured to output a display image as well as to allow the processedgeneral illumination light to pass through the display device. Thetransparent display device includes an array of display pixels. Eachdisplay pixel of the array includes a number of separately controllable,organic light emitting devices (OLEDs), and transparent areas in-betweenthe OLEDs formed from a transparent material.

An example of a transparent display device made up of an array ofdisplay pixels is also presented. Each display pixel of the arrayincludes a number of separately controllable, organic light emittingdevices (OLEDs) and transparent regions in-between the OLEDs. Thetransparent areas in-between the OLEDs are formed from a transparentmaterial. Each the OLEDs is constructed to emit visible light of adifferent respective one of three colors. A first of the OLEDs isstacked on a light emitting surface of the second of the OLEDs, and thesecond of OLEDs is stacked on a light emitting surface of the third ofthe OLEDs. In this arrangement, light from the emitting surface of thethird OLED passes through the second and first OLEDs, light from theemitting surface of the second OLED passes through the first OLED, andlight emerging from an emitting surface of the first OLED includes lightemitted by the first OLED as well as light emitted by the second andthird OLEDs.

In yet another example, a transparent display panel is described thatincludes an array of display pixels in which each display pixel hasthree separately controllable, OLEDs and transparent regions in-betweenOLEDs of the array. Each of the OLEDs is constructed to emit visiblelight of a different respective one of three colors; and in each pixelof the array, at least one of the three OLEDS comprises a tandem stackof two OLEDs. The tandem stack of two OLEDs is constructed to emitvisible light of a respective one of the three different colors.

In a further example, a transparent display panel is provided thatincludes an array of display pixels. The array of display pixelsincluding three separately controllable organic light emitting diodes(OLEDs) and transparent regions of the panel in-between OLEDs of thearray. Each of the OLEDs is constructed to emit visible light of adifferent respective one of three colors. The display pixels andtransparent regions are structured so that the transparent display panelexhibits an overall optical transmissivity with respect to at least thethree colors of light of 50% or more.

An example of a stacked light emitting device is also provided. Thestacked light emitting device includes a substrate, and a firstelectrode disposed on the substrate. A first organic OLED is disposedover the substrate and is electrically coupled to the first electrode. Asecond electrode is disposed over the first OLED and is electricallycoupled to the first OLED, and a second OLED is disposed over the secondelectrode and is electrically coupled to the second electrode. A thirdelectrode is disposed over the second OLED and is electrically coupledto the second OLED. A third OLED is disposed over the third electrodeand is electrically coupled to the third electrode. A fourth electrodeis disposed over the third OLED and electrically coupled to the thirdOLED. Each of the first, second, and third OLEDs emit light of one ofthree different colors.

Yet another example of the stacked light emitting device is providedthat includes a first OLED having a first color, a second OLED having asecond color, a third OLED coupled in a stacked orientation; and anelectrical connection connecting the first OLED, the second OLED, andthe third OLED together in series, wherein the electrical connectionapplies a voltage across the first OLED, the second OLED, and the thirdOLED.

Additional objects, advantages and novel features of the examples willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing and the accompanying drawings or may be learned by productionor operation of the examples. The objects and advantages of the presentsubject matter may be realized and attained by means of themethodologies, instrumentalities and combinations particularly pointedout in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations in accord withthe present concepts, by way of example only, not by way of limitations.In the figures, like reference numerals refer to the same or similarelements.

FIG. 1 is high-level functional block diagram of an example of alighting device of luminaire and associated driver and processingcomponents.

FIG. 2 is a high-level plan view of a luminaire, such as that of FIG. 1.

FIG. 3 is a high-level, top-view example of a portion of a transparentdisplay utilizing stacked OLEDs.

FIG. 4A illustrates a cross-section of an example of a stacked, activematrix controllable, OLED usable in an example of a transparent displaypanel.

FIG. 4B illustrates a cross-section of another example of a passivematrix controllable, OLED usable in an example of a transparent displaypanel.

FIG. 5A illustrates a top-view diagram of display pixel incorporating astacked, passive matrix (PM) OLED usable in an example of a transparentdisplay panel.

FIG. 5B illustrates a top-view diagram of a display pixel incorporatingan alternate electrode configuration.

FIG. 6A illustrates a cross-sectional view of an example of a stackedPMOLED of FIG. 5A or 5B.

FIG. 6B illustrates a cross-sectional view of an alternate example of astacked PMOLED of FIG. 5A or 5B.

FIG. 7 illustrates a top view example of a portion of a transparentdisplay panel utilizing multiple stacked, passive matrix-controllableOLEDs.

FIG. 8A illustrates an example of a display pixel using stacked OLEDshaving a reduced number of electrodes, in passive matrix-controllableOLED display panel.

FIG. 8B illustrates a tandem OLED suitable for use in a stacked OLEDstructure such as that shown in FIG. 8A.

FIG. 8C illustrates a modified example of the OLED of FIG. 8Aincorporating a tandem OLED, thereby forming a hybrid OLED.

FIGS. 8D, 8E and 8F show cross-sectional views of other examples ofstacked OLEDs, which incorporate reflective elements to increase theoptical efficiency of the respective OLEDs, e.g. for use in a PMOLEDused in a transparent display panel.

FIGS. 9A and 9B illustrate a simple example for controlling stackedOLEDs, in a passive matrix controllable OLED display.

FIG. 10 illustrates a simplified example of a process for constructing astacked OLED pixel, for use in a display pixel of a passive-matrixcontrollable OLED.

FIG. 11 is high-level functional block diagram of an example of adisplay device with associated driver and processing components.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent to those skilledin the art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, components,and/or circuitry have been described at a relatively high-level, withoutdetail, in order to avoid unnecessarily obscuring aspects of the presentteachings.

The various examples disclosed herein relate to a transparent displaydevice that generates an image but still permits subject matter behindthe transparent display to be visible to an observer of the imagepresented on the transparent display. The examples described in detailbelow and shown in the drawings typically implement one or moretechniques to enhance the transmissivity over currently existingtransparent display technologies. The increase in transparency may bebeneficial in many applications, including applications of the displayper se. The improved display also supports a dual functionality of adisplay and luminaire, particularly in a manner to more effectivelysupport luminaire type general lighting applications.

Throughout the detailed description, various terms will be used todescribe elements of the display, etc. that the reader may find help ifdescribed at the outset. For example, as used herein, a display pixelrefers to an OLED or a combination of two or more OLEDs that emit light,including OLEDs in a stacked arrangement or in combination of stackedand unstacked OLED structures, and that includes an area through whichlight passes substantially unobstructed, which is referred to as atransparent region or area. As used herein, the term “transparent”refers to a material having an optical transmissivity substantiallyequal to or greater than 35%. So, for example, a transparent displaypanel would be a display panel that has a transmissivity greater than35%. Examples of technologies are discussed below that alone or invarious combinations raise the transmissivity of the transparent displaypanel above this minimum and above levels achieved in existing displaypanels, particularly such panels using OLED-based pixels. Whenconsidered in the aggregate of a transparent display panel, atransparent area that comprises only glass and encapsulation may have alight transmissivity greater than 80%. A larger transparent area of thedisplay panel leads not only to higher overall transparency, but also acomparatively lesser usage of OLED devices and transparent conductormaterials.

The materials of the transparent, or clear, area(s) of the displaypixels will be substantially transparent and/or will produce relativelylittle or no diffraction of light passing through the display devicefrom the back going forward into the same area of illumination as lightemitted from the OLEDs of the display pixels of the panel. For visibledisplay and illumination applications, for example, the transparent(i.e. clear) area(s) of the display pixels will have a relatively highoptical transmissivity with respect to at least a substantial portion ofthe visible light spectrum, so as to appear clear or transparent to ahuman observer. Although the transparent area(s) may be transparent withrespect to almost all of or the entire visible spectrum, or even thevisible spectrum as well as some adjacent spectra of light, e.g. alsoinfrared (IR) light and/or ultraviolet (UV) light, the transparentarea(s) typically will be at least substantially transparent withrespect to the same colors of light emitted by the OLEDs of the pixeldisplay pixels of the panel (although in the examples, the OLEDemissions need not pass through the transparent area(s)). The degree oftransparency of the transparent area(s) of a display panel, e.g.transmissivity with respect to the relevant visible light, will at leastbe somewhat higher than that of the OLEDs of the pixel display pixels ofthe panel. For example, the transparent area(s) of the display panel maybe formed of glass and an appropriate encapsulation so as to exhibitlight transmissivity greater than 80% over the visible light spectrum.

Reference now is made in detail to the examples illustrated in theaccompanying drawings and discussed below. A high level example of aluminaire 11A as disclosed herein includes a lighting device 221 thatemits general illumination light, a spatial modulator device 223,collectively referred to as the controllable lighting system 111A, and atransparent display device 225. In addition, our example of theluminaire 11A includes other various components such as a driver system113A, a host processor system 115A, and a communication interface 117A.

The controllable lighting system 111A and the transparent display device225 will now be described in more detail in the context of the luminaire11A. The controllable lighting system 111A, in this example, includes alighting device 221 that emits general illumination light and a spatialmodulator device 223 that processes light emitted by the lighting device221 by providing beam shaping and/or beam steering functionality. Thelighting device 221 may be any light source suitable to emit generalillumination light of a sufficient intensity that the luminaire 11Acomplies with governmental guidelines or regulations and/or withindustry standards. The example of luminaire 11A is highlyconfigurable/controllable, therefore the lighting device 221 is a typethat is readily controllable, for example, with respect to luminanceoutput intensity and possibly other lighting parameters such asparameters relating to the spectral characteristics of the illuminationlight. For example, the lighting device 221 may be a controllablebacklight that is configured to output light in a fixed or selectabledirection. Examples of the lighting device 221 include variousconventional lamps, such as incandescent, fluorescent or halide lamps;one or more light emitting diodes (LEDs) of various types, such asplanar LEDs, micro LEDs, micro organic LEDs, LEDs on gallium nitride(GaN) substrates, micro nanowire or nanorod LEDs, photo pumped quantumdot (QD) LEDs, micro plasmonic LED, micro resonant-cavity (RC) LEDs, andmicro photonic crystal LEDs; as well as other sources such as superluminescent Diodes (SLD) and micro laser diodes. Of course, these lightgeneration technologies are given by way of non-limiting examples, andother light generation technologies may be used to implement thelighting device 221.

The spatial modulator device 223 processes light input into the device223 and outputs light having a specified beam shape and/or beamdirection. The spatial modulator 223, for example, includes an input232, controllable optics 233 and an output 235. The spatial modulatorinput 232 receives the general illumination light emitted by thelighting device 221, the controllable optics 233 spatially process theinput general illumination light, and the processed general illuminationlight is output via the output. The transparent display device 225 ofthe example luminaire 11A may be optically coupled to the output 235 ofthe spatial modulator device 223. The transparent display device 225,due to its transparent characteristics, allows a substantial quantity(e.g. 35% or higher amounts discussed in more detail later) of theprocessed general illumination light to pass through the display device225 and out to the environment in which the luminaire is located.

The transparent display 225 is configured to output a display image. Thetransparent display device 225 includes an array of display pixels, suchas display pixel 240. Each display pixel 240 of the array of displaypixels includes a number of separately controllable, organic lightemitting devices (OLEDs) 245 and transparent areas 247 in-between theOLEDs 245 of the transparent device 225. The transparent areas 247 areformed from a transparent material, such as glass or other material thatprovide similar optical performance. For example, if the glass or thelike is used as a substrate for the display panel, the OLEDs 245, eachof a limited area; and regions 247 of the transparent substratein-between the OLEDs form display pixels 240.

At a high-level, the transparent display device 225 outputs a displayimage in response to control signals received from the driver system113A. The displayed image may be a real scene, a computer generatedscene, a single color, a collage of colors, a video stream, or the like.In addition or alternatively, the image data may be provided to thetransparent display device 225 from an external source(s) (not shown),such as a remote server or an external memory device via one or more ofthe communication interfaces 117A. The functions of elements 111A and225 are controlled by the control signals received from the driversystem 113A. Similarly, the lighting device 221 provides generalillumination lighting in response to control signals and/or image datareceived from the driver system 113A.

The lighting device 221 and the spatial modulator device 223, althoughshown in combination as controllable lighting system 111A, may beconfigured as separate controllable devices that for ease of explanationare generally referred to as the controllable lighting system 111A.

As shown in FIG. 1, the spatial modulator device 223 is positioned inthe light output pathway of the lighting device 221. In general, thespatial modulator device 223 may include an input 232, controllableoptics 233 and an output 235: In the example, the input 232,controllable optics 233 and the output 235 are coupled to one another toenable the light emitted by the lighting device 221 to pass through thespatial modulator device 223. Examples of controllable optics 233 usableas a spatial modulator device 223 in the luminaire 11A are described indetail in one or more of U.S. Provisional Application Ser. Nos.62/193,859; 62/193,870; 62/193,874; 62/204,606; 62/209,546; and62/262,071, the contents of all of which are incorporated in theirentirety herein by reference. The input 232, for example, receives thegeneral illumination light emitted by the lighting device 221, passesthe inputted general illumination light to the controllable spatialmodulator device 233. The controllable spatial modulator device 233spatially processes the inputted general illumination light. Theprocessed general illumination light is output via output 235 and passedthrough the transparent display device 225 to provide generalillumination to the environment in which the luminaire 11A is located,for example, an illumination area within, overlapping with orencompassing an area from which a person may view the image presented bythe display device 225. In some examples, the controllable spatialmodulator device 233 is optional, and/or may be integrated in, or with,the lighting device 221 or the display 225.

In general, a controller, such as microprocessor 123A is coupled to thetransparent display device 225, and is configured to control the OLEDs245 of the display pixels 240 of the transparent display device 225 togenerate an image display by sending control signals to the displaydevice 225. The controller is also configured to control the lightingdevice 221 by sending control signals corresponding to generalillumination settings, such as brightness, color and the like, for thelighting device 221. Similarly, the controller is coupled to the spatialmodulator device 223 and is configured to control the controllableoptics 233 to process the general illumination light input from thelighting device 221.

In a specific example, the microprocessor 123A receives a configurationfile 128A via one or more of communication interfaces 117A. Theprocessor 123 may store, or cache, the received configuration file 128in storage/memories 125. The configuration file 128A includesconfiguration data that indicates, for example, an image for display bythe transparent display device 225 as well as lighting settings forlight to be provided by the configurable lighting device 11. Using theindicated image data, the processor 123A may retrieve from memory 125Astored image data, which is then delivered to the driver system 113A.The driver system 113A may deliver the image data directly to thetransparent display device 225 for presentation or may convert the imagedata into a format suitable for delivery to the transparent displaydevice 225. If not included in the configuration file for illumination,the image information for presentation on the display device 225 may beprovided separately, e.g. as a separate image file or as a video stream.

In another example, if the transparent display device 225 operates incooperation with the controllable lighting system 111A according toconfiguration data obtained from a configuration file associated withthe luminaire 11A. Each configuration file also includes softwarecontrol data to enable setting of light output parameters of thesoftware configurable lighting device at least with respect to thecontrollable lighting system 111A.

The processor 123A by accessing programming 127A and using softwareconfiguration information 128A, from the storage/memories 125A, controlsoperation of the driver system 113A, and through that system 113Acontrols the controllable lighting system 111A. For example, theprocessor 123A obtains distribution control data from a configurationfile 128A, and uses that data to control the driver system 113A to causethe display of an image via the transparent display device 225. Theprocessor 123A by accessing programming 127A and using softwareconfiguration information 128A also sets operating states of the lightgeneration and modulation components 221, 223 of the controllablelighting system 111A to generate illumination and to optically,spatially modulate output of a light source (not shown) of the lightingdevice 221 to produce a selected light distribution, e.g. to achieve apredetermined image presentation and a predetermined light distributionfor a general illumination application of a luminaire.

In other examples, the driver system 113A is coupled to the memory 125A,the transparent display device 225 and the controllable lighting system111A to control light generated by the transparent display device 225and the controllable lighting system 111A based on the configurationdata 128A stored in the memory 125A. In such an example, the driversystem 113A is configured to access configuration data 128A stored inthe memory 125A and generate control signals for presenting the image onthe transparent display device 225 and control signals for generatinglight for output from the general illumination device 111A.

FIG. 1 also provides an example of an implementation of the high layerlogic and communications elements and one or more drivers to drive thesource 110A and the spatial modulator 223 to provide a selected lightoutput distribution, e.g. for a general illumination application. Asshown in FIG. 1, the lighting device 11A may also include a hostprocessing system 115A, one or more sensors 121A and one or morecommunication interface(s) 117A.

The host processing system 115A provides the high level logic or “brain”of the device 11. In the example, the host processing system 115Aincludes data storage/memories 125A, such as a random access memoryand/or a read-only memory, as well as programs 127A stored in one ormore of the data storage/memories 125A. The data storage/memories 125Astore various data, including lighting device configuration information128A or one or more configuration files containing such information, inaddition to the illustrated programming 127A. The host processing system115A also includes a central processing unit (CPU), shown by way ofexample as the microprocessor (μP) 123A, although other processorhardware may serve as the CPU.

The ports and/or interfaces 129A couple the microprocessor 123A tovarious elements of the device 11A logically outside the host processingsystem 115A, such as the driver system 113A, the communicationinterface(s) 117A and the sensor(s) 121. For example, the processor 123Aby accessing programming 127A in the memory 125A controls operation ofthe driver system 113A and other operations of the lighting device 11Avia one or more of the ports and/or interfaces 129A. In a similarfashion, one or more of the ports and/or interfaces 129A enable theprocessor 123A of the host processing system 115A to use and communicateexternally via the interfaces 117A; and the one or more of the ports129A enable the processor 123A of the host processing system 115A toreceive data regarding any condition detected by a sensor 121A, forfurther processing. For example, one or more of sensors 121A may bepositioned behind transparent display panel 225 to enable detection ofconditions related to the environment in which the device 11A islocated. It is envisioned that sensors 121A such as a camera, a lightdetector, a time of flight sensor, an ambient color light detector,light communication detectors and emitters, a fluorescent analysissensor, a spectrometer and the like. The sensor(s) 121A may provideinformation to other devices, such as 11A as well as a buildingautomation system, an air conditioning system, or the like. In additionor alternatively, the sensor(s) 121A may communicate with systemsexternal to the environment in which the device 11A is located via theinterfaces 117A.

In the examples, based on its programming 127A, the processor 123Aprocesses data retrieved from the memory 123A and/or other data storage,and responds to light output parameters in the retrieved data to controlthe light generation and distribution system 111A. The light outputcontrol also may be responsive to sensor data from a sensor 121A. Thelight output parameters may include light intensity and light colorcharacteristics in addition to spatial modulation (e.g. steering and/orshaping and the like for achieving a desired spatial distribution).

As noted, the host processing system 115A is coupled to thecommunication interface(s) 117A. In the example, the communicationinterface(s) 117A offer a user interface function or communication withhardware elements providing a user interface for the device 11A. Thecommunication interface(s) 117A may communicate with other controlelements, for example, a host computer of a building control andautomation system (BCAS). The communication interface(s) 117A may alsosupport device communication with a variety of other systems of otherparties, e.g. the device manufacturer for maintenance or an on-lineserver for downloading of virtual luminaire configuration data.

As outlined earlier, the host processing system 115A also is coupled tothe driver system 113A. The driver system 113A is coupled to the lightsource 221 and the spatial modulator 223 to control one or moreoperational parameter(s) of the light output generated by the source 221and to control one or more parameters of the modulation of that light bythe spatial modulator 223.

The host processing system 115A and the driver system 113A provide anumber of control functions for controlling operation of the lightingdevice 11A. In a typical example, execution of the programming 127A bythe host processing system 115A and associated control via the driversystem 113A configures the lighting device 11 to perform functions,including functions to operate the light source 221 to provide lightoutput from the lighting device and to operate the spatial modulator 223to steer and/or shape the light output from the lighting device 221 soas to distribute the light output from the lighting device 11A based onthe lighting device configuration information 128A.

The device 11A is not size restricted. For example, each device 11A maybe of a standard size, e.g., 2-feet by 2-feet (2×2), 2-feet by 4-feet(2×4), or the like, and arranged like tiles for larger area coverage.Alternatively, the device 11A may be a larger area device that covers awall, a part of a wall, part of a ceiling, an entire ceiling, or somecombination of portions or all of a ceiling and wall.

The configuration of an example of the controllable lighting system 111Aand transparent display device 225 of FIG. 1 will now be described inmore detail with reference to FIG. 2. FIG. 2 is a high-level plan viewof a luminaire 200. The luminaire 200 includes a lighting device 210, aspatial modulator 220, and a transparent display device 250. In thisexample, the transparent display device 255 is an array of displaypixels 260, each of which include one or more OLED as shown at 257. Eachof the of display pixels 260 also includes a transparent area 259. Theexample of a panel of the transparent display device 255 also haselectrodes 265 and 267, which may extend into the areas of the displaypixels 260 for connection purposes. As shown the electrodes 265 and 267extend in a row and column arrangement interconnecting the respectivedisplay pixels 260 in the display pixel array of the transparent displaydevice 255. The electrodes 265 and 267 may be configured to implementeither an active matrix (with additional pixel-level circuitry not shownin this example) or a passive matrix control methodology of therespective OLEDs 257. The OLED 257 generates image display light.

As discussed above with respect to FIG. 1, the lighting device 210 emitsgeneral illumination light that complies with governmental regulationsand/or industry standards for the location of the luminaire 200. Thespatial modulator device 220 includes, for example, controllable optics,such as 233 of FIG. 1 above, that provide beam shaping and/or steeringfunctionality. As shown in FIG. 2, the general illumination lightemitted by the lighting device 210 is processed by the spatial modulatordevice 220 to have a particular light distribution selected inaccordance with configuration data. Although shown in FIG. 2 as beingsmaller in area than the transparent display device 255, the lightingdevice 210 may be as large as the transparent display or alternativelymay be smaller than actually shown. In the illustrated example, theprocessed general illumination light (shown as the heavier bold lines inFIG. 2) is directed to the beam steering and shaping zone 295.

The transparent display device 255 is optically coupled to the output ofthe spatial modulator device 220 and is configured to allow asubstantial portion of the general illumination light processed by thespatial modulator device 220 to pass through substantially unobstructed.The transparent display device 255, like device 225 of FIG. 1, includesan array of display pixels 260. As noted/shown, each of the displaypixels 260 in the array includes one or more OLEDs 257, a transparentarea 259, and portions of the electrodes 265 and 267. The electrodes 265and 267 deliver control signals from a driver, such as driver 113A ofFIG. 1, to the respective OLEDs 257. The transparent area 259 alsoincludes transparent parts of electrodes 265 and 267 and allows generalillumination light generated by the lighting device 210 to pass throughthe transparent display device 255 toward the beam steering and shapingzone 295 substantially unobstructed. The electrodes 265 and 267, whichwill be described in more detail in other examples, are configured to befabricated from a substantially transparent material, a translucentmaterial or are formed on components (e.g. wires of a mesh) so small orthin that they are nearly transparent, and as such permit some amount ofthe processed general illumination light to pass through the electrodes265 and 267. The OLEDs 257 also may allow some of the generalillumination light generated by the lighting device 210 that passesthrough the OLEDs 257.

As shown by the dashed lines coming out of the respective OLEDs 257, theimage display light emitted by the OLEDs 257 is directed out of thetransparent display device 255. Although not shown, the luminaire 200may also include a diffuser or other optics that are positioned at theoutput of the transparent display device. An example of the layout of anarray of display pixels of a transparent display device, such as 255,will be described in more detail with reference to FIG. 3.

As used herein, a display pixel 345 combination of the area filled bythe OLED 375 and the transparent area 379, and refers to an OLED or acombination of two or more OLEDs that emit light, including OLEDs in astacked arrangement or in combination of stacked and unstacked OLEDstructures. The transparent region or transparent area 379 allows lightto pass through substantially unobstructed. The array 300 that makes upa transparent display panel refers to the array of display pixels 345.

The OLEDs 375 of the array 300 are activated to generate image light toform an image that is output from the transparent display panel. Forexample, each of the OLED stacks 375 may be controlled as to color andintensity so as to produce light for a corresponding pixel of an imagethat is presented by the transparent display device. When referring tothe image generated by the transparent display panel, an image pixel isthe intended output of a corresponding display pixel 345.

FIG. 3 is a high-level, top-view example of a portion of a transparentdisplay utilizing stacked OLEDs. Examples of OLED stacks are discussedin more detail with regard to later drawings. In the view of FIG. 3 (asif looking into an array from a position to observe an emitted image)only the outline of the stack of OLEDs of each pixel is visible. Theunderlying driver electronics and control features of a typical displaydevice are explained in more detail with reference to the example ofFIG. 11. In the example of FIG. 3, a transparent display device is madeup of an array 300 of display pixels (i.e., pixels 345. Each displaypixel 345 of the display pixel array 300 includes a number of separatelycontrollable OLEDs 375 in a stack, and a transparent region, or area,379 in-between the stacked OLEDs 375 of the array of display pixels 300.Each the OLEDs 375 is, in some examples, three separately controllableOLEDs each constructed to emit visible light of a different one of threecolors, such as red, green and blue, white, blue, yellow, or othercombinations of colors. The three separately controllable OLEDs may bestacked one upon the other to create a stack of OLEDs that output acombination of red, green and blue light. Stacking of the OLEDs isbeneficial because the stack of OLEDs 375 reduces the area occupied bythe light emitting elements OLEDs 375 within the respective displaypixels 345 thereby increasing the optical transmissivity of thetransparent display.

As mentioned above with regard to this example, each display pixel 345includes a stacked OLED 375 and a transparent region 379 in-between thestacked OLEDs 375 of other display pixels 345 in the array 300. Thephysical sizes of the respective stacked OLED 375 and the transparentregions 379 contribute to the pixel pitch, which may be measured in thehorizontal and vertical dimensions. As shown in the example of FIG. 3,the vertical and horizontal pixel pitches are measured from a first sideof an OLED 375 to a corresponding first side of another OLED in animmediately neighboring display pixel 345. Since the display pixels 345of FIG. 3 are shown as squares, the vertical and horizontal pixelpitches are equal; however, in cases in which the display pixels 345 aredifferent shapes, such as rectangles or ovals, the vertical andhorizontal pixel pitches may differ.

The transparent areas 379 are formed from a transparent material, suchas clear areas of glass or other synthetic material having opticalproperties similar or superior to glass, that may be used as thesubstrate of the array. The transparent areas 379 may not be uniformlytransparent as some portions of the respective transparent areas 379 mayhave reduced transmissivity due to the presence of electrodes (not shownin this example) and/or circuitry (not shown in this example). In theexample, the transparent area 379 of each display pixel 345 encompassesa greater area than the OLED 375. For example, a ratio of the percentageof display pixel 345 area occupied by the OLED stack 375 to percentageof display pixel 345 area occupied by the transparent portion 379 isless than or equal to 80%:20%. While the OLED stack 375 is shownpositioned in a corner of the display pixel 345, the OLED stack may belocated at other locations, such as the center, another corner, off-setfrom center, offset from a corner or side (see for example, displaypixel 240 of FIG. 1), within the display pixel 345 so long as the ratioof area occupied by the OLED stack 375 to transparent area 379 remainsat approximately 20% to 80%.

It is envisioned that the percentage of display pixel 345 area occupiedby the OLED stack 37 will continue to diminish as the performance ofOLED devices improves. It is foreseeable that the ratio of thepercentage of display pixel 345 area occupied by the OLED stack 375 topercentage of display pixel 345 area occupied by the transparent portion379 will achieve ratios of 40%:60%, 30%:70, 20%:80% and even 5%:95%using OLED stacking techniques, vacuum evaporation/sublimationsmall-molecule OLED techniques, improved conductor technology, such assilver nanowire conductors, and additional coating techniques such asArgon coating.

By stacking the OLEDs 375 one upon the other, instead of placing thembeside one another laterally across the display pixel 345, the lightemitting parts of the transparent display consume less area of thedisplay pixel 345. As a result of the stacked OLED 375 taking up lessarea of the display pixel 345, the transparent area 379 may have alarger area thereby increasing the transmissivity of not only therespective display pixels 345, but the entire display array 300, andhence the transmissivity of the entire transparent display device isincreased. A benefit of the increased transmissivity of the displayarray 300, is that a greater amount of general illumination lightprovided by a lighting device, such as 221 of FIG. 1, can pass throughthe transparent display; although this increase in transmissivity andtransparency may serve to improve other applications of the displaydevice.

In an example in which the OLED stacks 375 emit three colors of light,the OLED stacks 375 and transparent regions 379 of the display pixels345 are structured so that the transparent display panel device exhibitsan overall optical transmissivity with respect to at least the threecolors of light of 50% or more. In other examples, the pixels 375 andtransparent regions 379 are structured so that the transparent displaydevice exhibits an overall optical transmissivity with respect to atleast the three colors of light of 60% or more. In further examples, thepixels 375 and transparent regions 379 are structured so that thetransparent display panel exhibits an overall optical transmissivitywith respect to at least the three colors of light of 70% or more. Asdescribed with respect to later examples, the pixels 375 and transparentregions 379 are structured so that the transparent display deviceexhibits an overall optical transmissivity with respect to at least thethree colors of light of 80% or more, and even approximately 85% ormore. The approximately 85% or more may be equal to approximately85%±5%. Of course, these improved levels of transmissivity may apply toother colors, frequencies or wavelengths of light in or near the visiblelight spectrum. These varied percentages of overall opticaltransmissivity may be achieved through the use of various OLEDtechniques, electrode design and materials and the like as described inmore detail with reference to the following examples.

It may be appropriate now to discuss the enhanced OLED techniques thatenable the increased transmissivity of the transparent display device.

FIG. 4A illustrates a cross-section of an example of a stacked, activematrix controllable, OLED usable in an example of a transparent displaypanel, such as that of FIGS. 1-3. In this example, the OLED stack 400for the display pixel is part of an active matrix.

A technique for reducing the area of the display pixel attributable tothe light emitting devices is to take advantage of the transparentproperties of OLEDs by stacking the different colored OLEDs on top ofone another. Active matrix (AM) OLEDs include transistors,interconnections and capacitors to switch the OLEDs ON and OFF. Thetransistors, interconnections and capacitors used in an AMOLED areopaque, which reduces the transmissivity of a transparent display panelthat utilizes active matrix control. The transistor circuits may includetwo or more transistors and one or more capacitive circuits. Forexample, some implementations include two transistors and a singlecapacitor, or even four transistors and two capacitors, both of whichenable faster ON/OFF switching. A method for increasing thetransmissivity of a pixel of an AMOLED display, by stacking OLEDs of thepixel, is illustrated in FIG. 4A.

In the example of FIG. 4A, the R (red), G (green) and B (blue) OLEDs arestacked one upon the other and are configured to emit light. OLEDs aresomewhat transparent, although not as highly transmissive as other clearmaterials such as glass. Hence the OLEDs in the stack also areconfigured to permit light, such as light (e.g. arrows labeled B)emitted by OLEDs (e.g. B and G) at the lower levels of the stack to passlight out of the OLED stack 400 for emission into the area in which theluminaire is located. Stacking the R, G and B OLEDs reduces the lesstransmissive area occupied by the display pixel and thereby increasesthe area that may be transparent. The transmissivity of a transparentdisplay panel may further be enhanced through use of transparent oxidematerials, and by orienting individual OLEDs in the OLED stack toposition the opaque transistor and interconnections over one another inthe stack to reduce the area covered by the opaque transistors andinterconnections of the stacked OLEDs as will be described in moredetail below.

For example, a first of the OLEDs, in this case OLED R, is stacked on alight emitting surface 409 of the second of the OLEDs, in this case OLEDG. OLED G, the second of the OLEDs, is stacked on a light emittingsurface of the third of the OLEDs, in this case OLED B.

As shown the light represented by arrows labeled B from the emittingsurface of the third OLED (i.e., OLED B) passes through the second, OLEDG, and through the first, OLED R. Similarly, light represented by arrowslabeled G) from the emitting surface of the OLED G passes through theOLED R. The light emerging from an emitting surface of the OLED Rincludes light emitted by the OLED R itself (represented by arrowslabeled R) as well as light emitted by the second (i.e. G) and third(i.e. B) OLEDs. For ease of illustration the light represented by arrowsRGB are shown emitting in one direction, it should be understood thatthe light may emit in multiple directions.

In more detail, the transistor circuits for each of the respective R, Gand B OLEDs are similar, and an example is described specifically withrespect to the transistor circuit associated with the R OLED. Theexample of the transistor circuit includes a gate electrode 402, adielectric layer 403, semiconductor transistor material 404, a sourceelectrode 405 a, and a drain electrode 405 b. The interconnections foreach of respective transistor circuits for R, G and B OLEDs includes ananode 406 and a cathode 409. The stack of OLEDs R, G and B may becovered on an output end by a transparent substrate 401, which may beformed from glass, a highly transmissive plastic, etc., and opposite thetransparent substrate 401 may be an encapsulation layer 410, which mayor may not be reflective. In the example, the OLED stack is configuredto emit intended display light through the transparent substrate 401.The OLED stacking technique, however, may be utilized in a pixelstructure may be configured to emit intended display light through theencapsulation layer 410 instead of through the substrate 401.

In order to increase the transparent area 411 in between the stackedOLEDs R, G and B, the area covered by the transistor circuits andinterconnections of each of the respective OLEDs R, G and B in the OLEDstack are positioned over other transistor circuits and interconnectionsof another OLED (e.g., R over G, and both over B) in the OLED stack. Forexample, the transparent area 411 for stacked AMOLED 400 may be formedfrom a transparent substrate. However, from a practical fabricationprocess and mechanical support standpoint, the space in betweentransparent substrates is usually filled by deposition of transparentmaterial, e.g. silicon dioxide or silicon nitride. This, for example,may help with planarization so that each display pixel on an overalldisplay panel is closely contacted.

Although not shown in detail, each of the OLEDs R, G and B of the OLEDstack 400 includes an organic layer 408 that is activated by the signalsfrom transistors applied to the anode 406 and cathode 409 of therespective OLEDs R, G and B. While not shown in detail, the organiclayer 408 is formed from several internal layers such as an electroninjection layer (EIL), an electron transport layer (ETL), an emissivelayer (EL), a hole transport layer (HTL), and a hole injection layer(HIL). The different colors of OLEDs may have different compositions ofmaterials for each of the respective internal layers. Regardless of thecolor of the OLED, the combination of layers, EIL, ETL, EL, HTL, andHIL, are referred to collectively as the organic layer 408.

The respective R, G and B OLEDs also include an electrical connectionfor applying a voltage across the first OLED, second OLED, and thirdOLED in the stack. Alternatively, the electrical connection delivers acurrent that is sufficient to excite the OLED.

Turning to the arrangement of the AMOLED arrangement shown in FIG. 4A,each respective display pixel in an array of display pixels includestransistor circuits, such as 402-404, 405 a and 405 b to activate therespective OLEDs in the respective display pixel. In addition to thetransistor circuits 402-404, 405 a and 405 b, interconnections betweenthe transistor circuits are used to configure the array as an activematrix OLED array of display pixels.

Element 411 of FIG. 4A represents a region of transparent material, suchas 379 of FIG. 3, that is in-between the stacked OLEDs R, G, B of therespective display pixel and stacked OLEDs (not shown in this example)of an adjacent display pixel. The transparent region 411 usuallyincludes glass and/or encapsulation with light transmissivity greaterthan 80%. By reducing the area consumed by the OLED and the relatedcircuitry, larger transparent areas may be incorporated into thetransparent display, such as 255, which leads to higher overalltransparency as well as reducing the usage of OLED and transparentconductor material by placing the OLEDs in closer proximity to oneanother. For example, active matrix control implemented using twotransistors and one capacitive circuit provides increased transmissivityand reduced costs as compared to the four transistor and two capacitivecircuit active matrix control, which provides higher performance but ata higher cost and reduced transmissivity.

Another type of OLED usable in a transparent display panel as discussedherein is a passive matrix (PM) OLED. FIG. 4B illustrates across-section of another example of a single, passive matrixcontrollable, OLED usable in an example of a stacked PMOLEDimplementation of a transparent display panel. A single PMOLED ispresented for ease of discussion and illustration.

The PMOLED 440 is usable as an emitter of a display pixel in a passivematrix-controlled transparent display. The PMOLED 440 has an activeregion 418 that emits light shown as light rays X and Z in response tocurrent or voltage signals applied to electrodes 419 (i.e. cathode) and416 (i.e. anode). The electrode 416 is disposed on a transparentsubstrate. The active region 418 is disposed on the electrode 416. Thetransparent substrate 421 may be made from glass, plastic or some othertransparent material. The side opposite the transparent substrate 421 iscovered with an encapsulation layer 141. The encapsulation layer 141 isalso formed from a transparent material, such as glass, plastic or someother transparent material. Beside the PMOLED 440 are transparentregions 4311. Additional examples of PMOLEDs will be described withreference to FIGS. 8A-10.

Although the OLED 400 is shown as a single stack of AMOLEDs (FIG. 4A) itis also envisioned that the OLEDs may be placed beside one another in acommon plane as an unstacked structure including transparent regionsthat form a display pixel in a transparent display panel. The singlePMOLED of FIG. 4B is shown for ease of discussion but it is envisionedthat the described OLED examples may be implemented using a number ofPMOLEDs in a stacked orientation.

In some examples, the transparent display may be configured for eitheractive matrix control or passive matrix control depending upon the pixeldensity of the transparent display panel.

As discussed above, one technique for increasing the transmissivity of atransparent display panel is to increase the area of the transparentregions by reducing the area of the array units that are consumed by theOLEDs and any associated opaque or low transmissivity components. Theelectrodes of the OLEDs are components that are not only associated withthe respective OLEDs but also are associated with the transparentregions. In order to interconnect the respective OLEDs in the array ofdisplay pixels, the electrodes must traverse the transparent regions.The materials used to construct the electrodes may be mildly opaque, ornear transparent, e.g. indium-tin-oxide (ITO) or the like. Currentmaterials typically used for the electrodes still absorb (i.e. trap),refract and/or reflect some of the light that is passing through atransparent region. In order to further increase the transmissivity of atransparent display panel, a way to limit the adverse impact of theelectrodes on light passing through the display panel will be describedwith reference to FIGS. 5A and 5B.

FIG. 5A illustrates a top-view diagram of an array display pixelsincorporating a stack of OLEDs, for a passive matrix (PM) OLED-typetransparent display panel. At a high-level, the array of display pixels500 of FIG. 5A includes an OLED stack 513, transparent regions 511, andelectrodes 565 and 567. In this example, each electrode 565 and 567 in amatrix of electrodes has a width that is substantially equivalent to orless than a width of a light emitting region of each respective OLEDstack 513. The electrode 565 may be a first electrode that is coupled toa first side of the OLED stack 513. The electrode 567 may be a secondelectrode that is coupled to a second side of the OLED stack 513. Theelectrodes 565 and 567 may be connected to PMOLED array type driver,such as may be included in driver system 113A of FIG. 1 or used toimplement video driver system 1113 of FIG. 11. The PMOLED array typedriver applies control signals to the respective electrodes toselectively activate the OLEDs of the pixel, in this case, the OLEDs ofthe stack 513.

As shown, the electrodes 565 and 567 consume nearly 50% of the area ofthe array of display pixel 500. The materials used to construct theelectrodes may be mildly opaque, or near transparent, e.g.indium-tin-oxide (ITO) or the like.

Further transmissivity improvement, over that possible with the use oftypical transparent electrode materials like ITO, may be desirable. Theelectrodes 565 and 567 have specific dimensions so that the currentdensity of the current passing through the respective electrodes 565 and567 is evenly distributed within the active regions of OLED stack 513.Therefore, simply reducing the size of electrodes to increase the areaof transparent region 511 is not a viable solution to increasetransparency of the display. However, the materials from which theelectrodes 565 and 567 are made may enable greater electrodetransparency thereby resulting in greater transmissivity of the displaypixel 500. For example, electrodes fabricated using silver nanowiresprovide high conductivity and increased transmissivity as compared tocurrent “transparent” electrodes such as indium-tin-oxide (ITO). Silvernanowire mesh (or a silver nanowire percolation network) can providehigher transmissivity and higher conductivity than broadly used ITO.

FIG. 5B illustrates a top-view diagram of an display pixel incorporatingan alternate electrode configuration. In addition to utilizing differentmaterials, as mentioned with respect to FIG. 5A, to fabricateelectrodes, the number of electrodes supplying an display pixel, such as501, may be increased so that each electrode in the matrix of electrodescoupled to each respective OLED includes a number of electrodes, such as565A-C and 567A-C, coupled to a side of a light emitting region of eachrespective OLED stack 513. So while the width of each of the number ofelectrodes is less than a dimension of the side of the light emittingregion of each respective OLED to which the number of electrodes iscoupled, the number of electrodes facilitates even distribution ofelectrical current to the light emitting region of each respective OLEDstack 513. As a result of increasing the number of electrodes andreducing the size of the electrodes, the area of transparent region ofthe display pixel not only includes transparent regions 511 but alsoincludes area 512 between each of the number of electrodes 565A-C and567A-C. The structure of the OLED stack 513 of FIG. 5A will be describedin more detail with reference to FIGS. 6A and 6B, which describevariations of the OLED 513 taken at the cross-section AA-AA.

FIG. 6A illustrates a cross-sectional view of an OLED stack 600 andneighboring transparent areas 611, for a passive matrix controllablePMOLED display. For example, the OLED and electrodes of the example ofFIG. 5A or of the example of FIG. 5B may be used as part of the stack inFIG. 6A.

The OLED stack 600 may include a first OLED 604 for emitting a firstcolor (e.g. blue), a second OLED 606 for emitting a second color (e.g.green), and a third OLED 608 coupled for emitting third color (e.g. red)in a stacked orientation. In addition, the OLED stack 600 also includesa number electrodes, such as 603, 605, 607 and 609, interconnecting eachOLED in the OLED stack of each respective display pixels in the array toform a passive matrix array coupled to an appropriate PMOLED typedisplay driver. Although conventional transparent electrode materialsmay be used, the e respective electrodes 603, 605, 607 and 609 may befabricated with conductors made using silver nanowire or othersmall-scale conductive materials, such as graphene or the like. Apassive matrix array differs from an active matrix array as describedwith reference to FIG. 4A in that a passive matrix does not require thetransistor circuitry and corresponding interconnections. As shown inFIG. 6A and described below, the OLEDs, 604, 606 and 608 in the OLEDstack 600 are coupled via a matrix of electrodes 603, 605, 607 and 609,to other OLEDs in an array. The electrodes 603, 605, 607 and 609 areconnected, respectively, to opposing sides of each OLED in the OLEDstack 600 to facilitate activation of the respective OLEDs 604, 606and/or 608.

With regard to the OLED stack 600, the OLED stack 600 may be formed on asubstrate 601, which may be glass or plastic. For discussion andillustration purposes only, the drawing shows an orientation in whichdisplay light is intended for emission from the stack in a directiontoward the top of the drawing. The OLEDs may generate some light in theopposite direction, but such light would be lost and not contribute tothe display function. Hence, a reflector 602 may be positioned on a sideof the substrate 601. The reflector 602 may be any form of reflectivesurface or device, such as one-way retro-reflector optic, such as acorner cube optic such as found in bicycle or automotive reflectors, orthe like. On a side of the substrate 601 opposite the reflector 601 is afirst electrode 603, which may be a row electrode of the PMOLED matrix,that couples to a side of an active region of a first colored OLED 604.The opposite side of the first-colored OLED 604 active region is coupledto a second electrode 605, which may be a column electrode of the PMOLEDmatrix. The second electrode 605 is also coupled to an active region ofthe second-colored OLED 606. The opposite side of the second-coloredOLED 606 active region is coupled to a third electrode 607, which may beanother row electrode. The third electrode 607 is also coupled to anactive region of the third-colored OLED 608. The opposite side of thethird-colored OLED 608 active region is coupled to a fourth electrode609, which may be a column electrode. On either side of the OLED stack600 are transparent regions 611 that (as shown in other examples, suchas FIG. 7) are in-between OLEDs of the array of a transparent displaypanel.

FIG. 6B illustrates a cross-sectional view of another example of an OLEDstack and neighboring transparent areas, for a passive matrixcontrollable PMOLED display. For example, the OLED and electrodes of theexample of FIG. 5A or of the example of FIG. 5B may be used as part ofthe stack in FIG. 6B. As previously mentioned an OLED stack correspondsto a display pixel, such as 375 of FIG. 3, of an array. For discussionand illustration purposes only, the drawing shows an orientation inwhich display light is intended for emission from the stack in adirection toward the top of the drawing.

Similar to the OLED stack structure of FIG. 6A, the OLED stack 610includes three separately controllable OLEDs, such as 623, 627 and 631,each of which is constructed to emit visible light of a differentrespective one of three colors. Also shown are transparent regions 621of the panel in-between OLEDs of the array. As shown in FIG. 6B anddescribed below, the OLEDs, 623, 627 and 631 in the OLED stack 610 arecoupled via a matrix of electrodes 622, 624, 626, 628, 630 and 632 thatare connected to opposing sides of each OLED in the OLED stack 610 tofacilitate activation of the respective OLEDs 623, 627 and/or 631.Although conventional transparent electrode materials may be used, therespective electrodes 622, 624, 626, 628, 630 and 632 may be fabricatedwith conductors made using silver nanowire mesh, silver nanowirepercolate network, or other small-scale conductive materials, such asgraphene or the like.

The OLED stack 610 of FIG. 6B may be formed on a substrate 621. Thesubstrate 621 may be made from glass or plastic. For discussion andillustration purposes only, the drawing shows an orientation in whichdisplay light is intended for emission from the stack in a directiontoward the top of the drawing. The OLEDs may generate some light in theopposite direction, but such light would be lost and not contribute tothe display function. On a side of the substrate 621 is a firstelectrode 622, which may be a row electrode of the PMOLED matrix, thatcouples to a side of an active region of a first colored OLED 623. Theopposite side of the first-colored OLED 623 active region is coupled toa second electrode 624, which may be a column electrode of the PMOLEDmatrix. A transparent insulator 625 separates the first-colored OLEDfrom a third electrode 626. The third electrode 626, which may beanother row electrode, is coupled to an active region of thesecond-colored OLED 627. The opposite side of the second-colored OLED627 active region is coupled to a fourth electrode 628, which may beanother column electrode. The fourth electrode 628 is insulated from thethird-colored OLED 631 by transparent insulator 629. Upon thetransparent insulator 629 is a fifth electrode 630, which may be a rowelectrode, that is coupled to an active region of the third-colored OLED631. The opposite side of the third-colored OLED 631 active region iscoupled to a sixth electrode 632, which may be a column electrode. Oneither side of the OLED stack 610 are transparent regions 621 that (asshown in other examples, such as FIG. 7) are in-between OLEDs of thearray of a transparent display panel.

FIG. 7 illustrates a top view example of a portion of a transparentdisplay panel utilizing multiple stacked, passive matrix-controllableOLEDs. The portion 700 of a transparent display panel shows displaypixels 711-714. The display pixels 711-714 include respective stackedRGB emitters 775-778 formed on OLEDs. The display pixels 711-714 alsoinclude transparent areas 721-724. It should be noted that, in theillustrated example, the transparent areas 721-724 surround therespective stacked RGB emitter 775-778. Each stacked RGB emitter 775-778in respective display pixels 711-714 is interconnected with a rowelectrode, such as row electrode 783 or 785 and column electrode 784 or786 to form a passive matrix array. The interconnections of therespective OLEDs in the stacked RGB emitters 775-778 will described inmore detail with reference to FIG. 8A and FIGS. 9A and 9B.

As mentioned above, the transparent area of a transparent display panel,and hence the overall optical transmissivity of the transparent displaypanel may be increased by reducing area consumed by obstructingcircuitry and/or components and by using more transparent materials. Inaddition, the electrodes trap light emitted by the respective OLEDsthereby reducing the overall optical efficiency of the stacked OLEDs.Another technique for increasing transmissivity that also increases theoptical efficiency of the OLED stack, is to reduce the number ofcomponents that contribute to the reduced transmissivity and opticalefficiency. While individual electrodes may only occlude a minimalamount of light that would pass through a transparent display panel,particularly the transparent area of the display pixel, when utilized inthe stacked OLED configuration examples described herein, the occludingeffect may be cumulative thereby having a noticeable negative effect onthe overall optical transmissivity of the transparent display panel. Onetechnique for limiting the cumulative transmissivity limiting effects ofthe electrodes and reducing the amount of light trapping in therespective layers is to reduce the number of electrodes. As will beexplained with reference to FIG. 8A, the PMOLED configuration providesan opportunity to implement a reduced electrode example.

FIG. 8A illustrates an example of stacked, passive matrix-controllableOLED having a reduced number of electrodes. The stacked PMOLED 800 ofFIG. 8A is a stacked light emitting device formed on a substrate 801. Afirst electrode 802, which may be a column or row electrode,respectively, is disposed on the substrate 801. A first PMOLED 803 thatemits light of a first color is disposed over the substrate 801 and iselectrically coupled to the first electrode 802. A second electrode 804is disposed over the first PMOLED 803. The second electrode 804 iselectrically coupled to the first PMOLED 803. The second electrode 804may electrically couple to a first side of an active region (not shownin this example) of the first PMOLED 803 A second PMOLED 805 is disposedover and is electrically coupled to the second electrode 804. Forexample, the electrode 804 also electrically couples to an active regionof the second PMOLED 805 opposite to the connection of the secondelectrode 804. In this way, the second electrode 804 provides electricalconnection to active regions of both OLEDs 803 and 805 of the stack. Athird electrode 806 is disposed over and is electrically coupled to thesecond PMOLED 805. A third OLED 807 is disposed over and is electricallycoupled to the third electrode 807 at an active region of the third OLED807. Hence, the third electrode 806 provides electrical connections toboth OLEDs 805 and 807. Disposed over the third OLED 807 is a fourthelectrode 808 that is also electrically coupled to the third OLED 807.In some examples, the first, second, and third OLEDs, each emit light ofone of three different colors. For example, the OLED 807 may emit redlight, the OLED 805 may emit green light and the OLED 803 may emit bluelight. The generated amounts of each output color are based on controlsignals. Alternatively, the respective OLEDs 803, 805 and 807 of OLEDstack 800 may emit light of the same color, such as R, R, R, ordifferent combinations, such as G, B and B.

Although not shown in detail, each of the OLEDs 803, 805 and 807 includeadditional components and structure such as anodes, cathodes and layersforming active regions that are coupled to the respective electrodes802, 804, 806 and 808, similar to the respective layers shown in theexample of FIG. 4B. As mentioned above, the number of electrodes in thePMOLED 800 is reduced compared to a stacked PMOLED such as that shown inFIG. 6B. The stacked OLED 800, instead of utilizing six (6) electrodes,uses four electrodes. As shown to the left of the stacked OLED 800 is asimple circuit diagram in which the respective OLEDs 803, 805, and 807in the stacked OLED 800, are represented by diodes I, II and III,respectively. An example of the circuit operation will be described inmore detail with reference to FIGS. 9A and 9B.

In addition to reducing the number of electrodes to increase overalltransmissivity and improve the optical efficiency of the transparentdisplay panel, the reduced number of electrodes may also incorporatematerials as conductors, such as silver nanowires or the like, in theelectrodes to further reduce the occluding caused by the number ofelectrodes. For example, electrodes 802, 804, 806 and 808 may befabricated with transparent materials that incorporate a mesh of silvernanowires as conductors.

As mentioned above, the OLED stack 800 may be configured to emit lightusing a combination of OLEDs of the colors, Green, Blue and Blue. Amethod of forming a tandem OLED, such as a Blue-Blue, that uses areduced number of electrodes is illustrated in FIG. 8B. FIG. 8Billustrates a tandem OLED suitable for use in a stacked OLED structuresuch as that shown in FIG. 8A. The tandem OLED 820 of FIG. 8B includes atransparent substrate 821, an anode 822, a first OLED 823, a chargegeneration layer 824, a second OLED 825 and a cathode 828. All of therespective elements 821-825 may be transparent to enable the lightgenerated by the tandem OLED 820 to be output from the respective OLEDs825, 823.

In response to a voltage applied by voltage source V across the anode822 and cathode 828, each of the first OLED 823 and the second OLED 824outputs light of the same color, such as blue. In an example in whichthe cathode 828 is reflective, and reflects light in the direction ofthe second OLED 825, substantially all the blue light generated by thesecond OLED 825 passes through the charge generation layer 824, thefirst OLED 823, the anode 822 and the transparent substrate 821, and isoutput in the direction of the arrows A benefit of this configuration isthat the tandem OLED enables the brightness of the OLED stack toincrease as the output light of a particular color is increased and alsoenables the number of electrodes to be reduced due to the use do thecharge generation layer 824. The area of the stack on the substrate,however, may be comparable to the substrate area for a single OLED.

In a simplified description, the charge generation layer 824 contributesholes to the second OLED 825 which receives electrons from the cathode828 to enable the second OLED 825 to produce light. Conversely, thecharge generation layer 824 contributes electrons to the first OLED 823which receives holes from the anode 822 to enable the first OLED 823 toproduce light.

The example of FIG. 8C illustrates a modification of the OLED 800 ofFIG. 8A to incorporate a tandem OLED 820 of FIG. 8B, thereby forming aOLED 800′. In FIG. 8C, the third OLED 807 of FIG. 8A is replaced withthe combination of the first OLED 823′, the charge generation layer824′, the second OLED 825′ to form a OLED stack having four OLEDs 803′,805′, 823′ and 825′. In which, the third OLED and the fourth OLEDs, inthis case OLEDs 823′ and 825′ output light of the same color. Thecircuit connections I, II and III as shown in FIG. 8A remain the sameeven though an extra OLED 825′ has been added in the OLED stack 800′.The added OLED 825′ requires an increased voltage to be applied toaccount for the additional OLED in the OLED stack 800′.

FIGS. 8D, 8E and 8F show cross-sectional views of other examples ofstacked, passive matrix controllable OLEDs that incorporate reflectiveelements to increase the optical efficiency of the respective OLEDstacks. The OLED stacks of FIGS. 8D-8F are substantially similar to theOLED stack described with reference to FIG. 8A, so therefore a detaileddescription of the respective layers will not be included for ease ofdescription. As described herein, the individual OLEDs in the OLEDstacks output light in all directions, but for ease of discussion andillustration the light emission is shown in two directions.

In FIG. 8D, the OLED stack 880 includes various electrodes and a numberof OLEDs, such as 883, 885 and 886 that emit light, shown by therespective arrows J, K and L. The OLED stack 880 includes a reflectivelayer 884 disposed on a side of an electrode 882 opposite an OLED 882and adjacent to the substrate 881 in the stack of OLEDs 880. As shown,light (arrow L) emitted by OLED 886 is emitted in the direction towardthe substrate 881. The light (arrow L) is reflected by the reflectivelayer 884 and output through the other OLEDs, such as 883, 885 and 886,and electrodes, such as 882, of the OLED stack 880. Alternatively, thepositions of reflective layer 884 and the electrodes 882 may be switchedso that the reflective layer 884 is disposed on a side of the electrode882. The reflective layer 884 may be a mirrored surface, a metallicsurface or other material that reflects light emitted by the respectiveOLEDs, such as 883, 885 and 886, in the OLED stack 880. Although notshown, the OLED 886 also emits some light directly through theencapsulant as part of the intended output of stack 800. Also, the otherOLEDs emit some light for reflection (e.g. downward) and some light moredirectly toward the output (e.g. upward). Alternatively, the electrode882 and the reflective layer 884 may be replaced with a reflectiveelectrode layer made from, for example, silver or aluminum, whichpossess both high optical reflectivity and electrical conductivity.

In another example as shown in FIG. 8E, a reflective layer 894 ispositioned at an end of the OLED stack 890. The reflective layer 894reflects light, such as arrow V and T, emitted by the respective OLEDs892 and 893 out of the OLED stack 890 via a transparent substrate 891which may generally be shown by arrows S, U and W. Arrow S may alsorepresent light emitted by OLED 892. The reflective layer 894 may be amirrored surface, a metallic surface or other material that reflectslight emitted by the respective OLEDs, such as 892 and 893, in the OLEDstack 890.

In the example of FIG. 8F, the OLED stack 878 includes OLEDs andelectrodes in a stacked orientation, that is collectively referred to byreference numeral 873. The stack 878 also includes a substrate 872 and aone-way reflector 871. The OLEDs 873 are stacked upon substrate 872, andover the one-way reflector 871. The one-way reflector 871 is a material,such as a film, or a one-way retro-reflective optic, such as acorner-cube optic used in an automobile reflector, that permits lightfrom outside the display (e.g. from a lighting device such as 221 ofFIG. 1). The reflector 871, however, reflects light emitted by the OLEDs873, such as, for example, light represented by arrow G, that maycontribute to the output light shown by arrows H and I.

FIGS. 9A and 9B illustrate a simple example for controlling passivematrix controllable OLED stacks. An example of a portion of an array ofdisplay pixels 900 is shown for illustration purposes having only 9 OLEDstacks and corresponding row and column electrodes that interconnect therespective OLEDs of the array. For ease of explanation, only the controlof OLED stacks 911, 921 and 931 will be described in detail. However, asimilar description applies to other OLED stacks in the array The OLEDstacks of 911, 921 and 931 include three OLEDs and correspondingelectrodes, however, the scheme illustrated in FIG. 9A will scale to anynumber of OLEDs in each OLED stack. It should be noted that transparentregions of the array of display pixels 900 are not shown for ease ofdescription of the examples of FIGS. 9A and 9B.

The scheme of FIG. 9A shows an example of how four independentelectrodes (2 row electrodes and 2 column electrodes) may be usedcontrol a column of three OLED stacks 911, 921 and 931. In the example,when two row electrodes, such as V11, V111 in the top row R1 are drivenby an input voltage of, for example, 11 volts and 3 volts, respectively,and at the same time, two column electrodes such as V29 and V49 in leftcolumn C1 are driven by input voltages of 8 volts and 0 volts,respectively. In response to the respective voltages, only the OLEDstack 911 emits light because the OLED driving voltage for each OLED inthe different stack layers is 3 volts, 5 volts, and 3 volts,respectively.

When two row electrodes in the middle row are driven by input voltage of12 volt and 5 volt, respectively, and at the same time, two columnelectrodes in left column are driven by input voltage of 6 volt and 0volt, respectively, only OLED 921 emits light because the OLED drivingvoltage for each OLED in the different stack layers is 6 volts, 1 volts,and 5 volts, respectively.

When two row electrodes in bottom row are driven by input voltage of 10volts and 3 volts, respectively, and at the same time, two columnelectrodes in left column are driven by input voltage of 7 volts and 0volts, respectively, only OLED 931 emits light because the OLED drivingvoltage for each OLED in the different stack layers is 3 volts, 4 volts,and 3 volts, respectively.

It is worth noting that only three (3) independent input voltages arerequired to drive a tandem OLED structure with three (3) layers ofOLEDs. The fourth electrode could be always ground to ease the drivingcomplexity and to reduce the number of driving channels required.

Different color and/or brightness for each display pixel can be tuned bythe combination of 3 different operating voltages that may be directlycontrolled by 3 independent input voltages V1, V2, and V3 while V4 isalways ground.

FIG. 9B illustrates a simple example for controlling stacked OLEDs, in apassive matrix controllable OLED display. For an OLED structure, such asthat shown in FIG. 8A, with three (3) layers of OLED, there are four (4)independent electrodes whose input voltages are represented by V1, V2,V3, and V4, respectively. Each OLED emits light by applying a sufficientforward voltage, i.e. an input voltage at an anode of the OLED that ishigher than the input voltage at cathode of the OLED. The voltagedifference between the anode and the cathode is the applied operatingvoltage of the respective OLED. Output optical power can be tuned bytuning the operating voltage. In this case, the operating voltage ofOLED I is V1 minus (−)V2. The operating voltage of OLED II is V2−V3. Theoperating voltage of OLED III is V3−V4. For example, when V1, V2, V3, V4are 11 volts, 8 volts, 3 volts, 0 volts, respectively, the correspondingoperating voltage for OLED I, II, and III is 3 volts, 5 volts, and 3volts, respectively.

FIG. 10 illustrates a simplified example of a process for constructing astacked, passive-matrix controllable OLED in a display pixel. In thesimplified example, the process 1000 may begin at step 1010 bydepositing on a substrate 1011 a first electrode 1012, which for ease ofexplanation will be referred to as row electrode. Although the substrate1011 may be large, to support many OLED stacks, for convenience thedrawing shows an area of a substrate approximately corresponding to thearea of the display pixel that will include the OLED stack.

Upon the row electrode 1012 is deposited, at 1020, the layers forming afirst OLED 1024 of an OLED stack. At step 1030, the first columnelectrode 1021 is deposited on the OLED 1024. Deposited, at 1040, overthe column electrode 1021 is a second OLED 1044. As the process 1000proceeds to step 1050, a second row electrode 1052 is deposited on theOLED 1044. Disposed on second row electrode 1052 at step 1060 is thirdOLED 1064. At step 1070, the second column electrode 1071 is depositedover the OLED 1064, which completes the OLED stack as shown at 1080. TheOLED stack may be generated using techniques such as silk screening,inkjet printing, gravure printing techniques or the like.

FIG. 11 is high-level functional block diagram of an example of adisplay device with associated driver and processing components. Theexample device 1100 includes a host processing system 1115,communication interfaces 1117, a video driver system 1113, and atransparent display device 1225.

The transparent display 1225 is configured to output a display image.The transparent display device 1225 includes an array of display pixels,such as display pixel 240. Each display pixel 1240 of the array ofdisplay pixels includes a number of separately controllable, organiclight emitting devices (OLEDs) 1245 and one or more transparent areas1247 adjacent to the OLEDs 1245 of the display pixel 1240. Thetransparent areas 1247 are formed from a transparent material, such asglass or other material that provide similar optical performance. Forexample, if the glass or the like is used as a substrate for the displaypanel, the OLEDs 1245 occupy limited areas; and regions of thetransparent substrate in-between as the transparent regions or areas ofthe display pixel of the panel.

At a high-level, the transparent display device 1225 outputs a displayimage in response to control signals received from the driver system1113. The displayed image may be a real scene, a computer generatedscene, a single color, a collage of colors, a video stream, or the like.In addition or alternatively, the image data may be provided to thetransparent display device 1225 from an external source(s) (not shown),such as a remote server or an external memory device via one or more ofthe communication interfaces 1117. In addition to the display function,the transparency of the device 1225 allows light to pass through thedevice 1225. For example, when viewing a displayed image, a viewer canalso see objects behind the device 1225 through the device 1225.

The functions of transparent display device 1225 are controlled by thecontrol signals received from the driver system 1131. The driver system111A may deliver the image data directly to the transparent displaydevice 1225 for presentation or may convert the image data into a formatsuitable for delivery to the transparent display device 1225. The imageinformation for presentation on the display device 225 may be providedseparately, e.g. as a separate image file or as a video stream. Theprocessor 1123 by accessing programming and using a softwareconfiguration information stored in the storage/memories 1125, controlsoperation of the video driver system 1113. For example, the processor123A obtains distribution control data from ROM 1127 or RAM 1122 anduses that data to control the video driver system 1113 to cause thedisplay of an image via the transparent display device 1225.

FIG. 11 also provides an example of an implementation of the high layerlogic and communications elements and to provide an output image. Thehost processing system 1115 provides the high level logic or “brain” ofthe device 1100. In the example, the host processing system 1115includes data storage/memories 1125, such as a random access memory 1122and/or a read-only memory 1127, as well as programs stored in one ormore of the data storage/memories 125A. The data storage/memories 1125store various data. The host processing system 1115 also includes acentral processing unit (CPU), shown by way of example as themicroprocessor (μP) 123A, although other processor hardware may serve asthe CPU.

The ports and/or interfaces 1129 couple the microprocessor 1123 tovarious elements of the device 1100 logically outside the hostprocessing system 1115, such as the video driver system 1113, and thecommunication interface(s) 1117. For example, the processor 1123 byaccessing programming in the memory 1125 controls operation of the videodriver system 1113 and other operations of the device 1100 via one ormore of the ports and/or interfaces 1129. In a similar fashion, one ormore of the ports and/or interfaces 1129 enable the processor 1123 ofthe host processing system 1115 to use and communicate externally viathe interfaces 1117.

As noted, the host processing system 1115 is coupled to thecommunication interface(s) 1117. In the example, the communicationinterface(s) 1117 offer a user interface function or communication withhardware elements providing a user interface for the device 1100. Thecommunication interface(s) 1117 may communicate with other controlelements, for example, a host computer of an image or media contentprovider server, an external media device or the like. The communicationinterface(s) 117A may also support device communication with a varietyof other systems of other parties, e.g. the device manufacturer forupdated or an on-line server for downloading of digital media content,image data, or the like.

Specific examples and additional details of the of luminaires, lightsources, and spatial modulators as well as associated driver, controland communication components, e.g. for use in software configurableluminaires, may be found in applicant's related applications, U.S.Provisional Applications Nos. 62/193,859; 62/193,870; 62/193,874;62/204,606; 62/209,546; and 62/262,071, which are all incorporated intheir entirety herein by reference.

The term “coupled” as used herein refers to any logical, physical orelectrical connection, link or the like by which signals produced by onesystem element are imparted to another “coupled” element. Unlessdescribed otherwise, coupled elements or devices are not necessarilydirectly connected to one another and may be separated by intermediatecomponents, elements or communication media that may modify, manipulateor carry the signals.

It will be understood that the terms and expressions used herein havethe ordinary meaning as is accorded to such terms and expressions withrespect to their corresponding respective areas of inquiry and studyexcept where specific meanings have otherwise been set forth herein.Relational terms such as first and second and the like may be usedsolely to distinguish one entity or action from another withoutnecessarily requiring or implying any actual such relationship or orderbetween such entities or actions. The terms “comprises,” “comprising,”“includes,” “including,” or any other variation thereof, are intended tocover a non-exclusive inclusion, such that a process, method, article,or apparatus that comprises a list of elements does not include onlythose elements but may include other elements not expressly listed orinherent to such process, method, article, or apparatus. An elementpreceded by “a” or “an” does not, without further constraints, precludethe existence of additional identical elements in the process, method,article, or apparatus that comprises the element.

Unless otherwise stated, any and all measurements, values, ratings,positions, magnitudes, sizes, and other specifications that are setforth in this specification, including in the claims that follow, areapproximate, not exact. They are intended to have a reasonable rangethat is consistent with the functions to which they relate and with whatis customary in the art to which they pertain.

While the foregoing has described what are considered to be the bestmode and/or other examples, it is understood that various modificationsmay be made therein and that the subject matter disclosed herein may beimplemented in various forms and examples, and that they may be appliedin numerous applications, only some of which have been described herein.It is intended by the following claims to claim any and allmodifications and variations that fall within the true scope of thepresent concepts.

What is claimed is:
 1. A luminaire, comprising: a lighting device thatemits general illumination light; a spatial modulator device comprising:an input that receives the general illumination light emitted by thelighting device; controllable optics that spatially process the inputgeneral illumination light; and an output that outputs the processedgeneral illumination light; a transparent display device opticallycoupled to the output of the spatial modulator device and configured tooutput a display image and allow the processed general illuminationlight to pass through the display device, the transparent display devicecomprising: (a) an array of display pixels, wherein each display pixelof the array includes a number of separately controllable, organic lightemitting devices (OLEDs); and (b) transparent areas in-between the OLEDsformed from a transparent material.
 2. The luminaire of claim 1, whereinthe number of OLEDs are stacked one upon the other to form an OLEDstack.
 3. The luminaire of claim 2, wherein, in each display pixel ofthe array of display pixel pixels, the stacked OLEDs include: threeseparately controllable OLEDs each constructed to emit a different oneof three colors.
 4. The luminaire of claim 2, wherein each display pixelof the array of display pixels comprises: a first of the number of OLEDsbeing stacked on a light emitting surface of a second of the OLEDs andthe second of the number of OLEDS being stacked on a light emittingsurface of a third of the number of OLEDs so that: light from theemitting surface of the third OLED passes through the second and firstOLEDs, light from the emitting surface of the second OLED passes throughthe first OLED, and light emerging from an emitting surface of the firstOLED includes light emitted by the first OLED as well as light emittedby the second and third OLEDs.
 5. The luminaire of claim 4, wherein thetransparent material of the transparent area is located in-between thestacked OLEDs of the respective display pixel and stacked OLEDs of anadjacent display pixel.
 6. The luminaire of claim 1, further comprising:a controller coupled to the display device and configured to control theOLEDs of the display pixels of the array and to control the lightingdevice, wherein the controller provides control signals to the displaydevice and the lighting device for display and general illuminationsettings.
 7. The luminaire of claim 6, wherein the controller isfurther: coupled to the controllable optics of the spatial modulatordevice; and configured to control spatial processing of the inputgeneral illumination light by supplying spatial modulation controlsignals to the controllable optics.
 8. The luminaire of claim 2, whereinthe respective display pixels in the array of display pixels includes: atransistor circuit associated with each OLED in the stack of OLED toactivate each of the OLEDs of the respective display pixel; andinterconnections to the transistor circuits associated with each OLED inthe stack of OLEDs to configure the array as an active matrix OLEDarray.
 9. The luminaire of claim 8, wherein the transistor circuits andinterconnections of each of the respective OLEDs in the OLED stack arepositioned over other transistor circuits and interconnections ofanother OLED in the OLED stack.
 10. The luminaire of claim 8, whereinthe transistor circuits comprise two or more transistors and one or morecapacitive circuits.
 11. The luminaire of claim 2, wherein the array ofdisplay pixels includes: a number electrodes interconnecting each OLEDin the OLED stack of each respective display pixels in the array to forma passive matrix array.
 12. The luminaire of claim 11, wherein each OLEDin the OLED stack in the respective display pixel in the passive matrixarray includes: a first electrode coupled to a first side of the OLED;and a second electrode coupled to a second side of the OLED, wherein theOLED is activated by electrical current passing between the firstelectrode and the second electrode.
 13. The luminaire of claim 11,wherein the OLEDs in the OLED stack are coupled via a matrix ofelectrodes connected to opposing sides of each OLED in the OLED stack tofacilitate activation of the respective OLED.
 14. The luminaire of claim13, wherein each electrode in the matrix of electrodes has a width thatis substantially equivalent to or less than a width of a light emittingregion of each respective OLED.
 15. The luminaire of claim 14, whereineach electrode in the matrix of electrodes coupled to each respectiveOLED comprises a number of electrodes coupled to a side of a lightemitting region of each respective OLED to facilitate even distributionof electrical current to the light emitting region of each respectiveOLED, wherein the width of each of the number of electrodes is less thana dimension of the side of the light emitting region of each respectiveOLED to which the number of electrodes is coupled. 16-43. (canceled) 44.A luminaire, comprising: a lighting device that emits generalillumination light; a transparent display device optically coupled tothe lighting device and configured to output a display image and allowthe general illumination light to pass through the display device, thetransparent display device comprising: (a) an array of display pixels,wherein each display pixel of the array includes a number of separatelycontrollable, organic light emitting devices (OLEDs); and (b)transparent areas in-between the OLEDs formed from a transparentmaterial, wherein a ratio of a percentage of display area occupied bythe OLEDs to a percentage of the display area occupied by thetransparent areas is less than 80%:20%.
 45. The luminaire of claim 44,further comprising: a spatial modulator device comprising: an input thatreceives the general illumination light emitted by the lighting device;controllable optics that spatially process the input generalillumination light; and an output that outputs the processed generalillumination light, wherein the transparent display is configured tooutput the display image and allow the processed general illuminationlight to pass through the display device.
 46. The luminaire of claim 44,wherein the number of OLEDs are stacked one upon the other to form anOLED stack.
 47. The luminaire of claim 46, wherein the array of displaypixels includes: a number electrodes interconnecting each OLED in theOLED stack of each respective display pixels in the array to form apassive matrix array.
 48. The luminaire of claim 46, wherein, in eachdisplay pixel of the array of display pixel pixels, the stacked OLEDsinclude: three separately controllable OLEDs each constructed to emit adifferent one of three colors.
 49. The luminaire of claim 46, whereinthe respective display pixels in the array of display pixels includes: atransistor circuit associated with each OLED in the stack of OLEDs toactivate each of the OLEDs of the respective display pixel; andinterconnections to the transistor circuits associated with each OLED inthe stack of OLEDs to configure the array as an active matrix OLEDarray.